macOS: Don't produce NSImages without a single representation

Doing so results in exceptions inside AppKit when passed on to APIs that
expect valid images. It's better to produce nil-images.

Fixes: QTBUG-83494
Change-Id: I1e5bfa2a7fecd75a1ddb95bd1a6dc2e8db6b24f8
Reviewed-by: Volker Hilsheimer <volker.hilsheimer@qt.io>

1 files changed, 6 insertions, 3 deletions

diff --git a/src/gui/painting/qcoregraphics.mm b/src/gui/painting/qcoregraphics.mm
index 94ba004c93..7fb075d19e 100644
--- a/src/gui/painting/qcoregraphics.mm
+++ b/src/gui/painting/qcoregraphics.mm
@@ -162,12 +162,12 @@ QT_END_NAMESPACE
     if (icon.isNull())
         return nil;
 
-    auto nsImage = [[NSImage alloc] initWithSize:NSZeroSize];
-
     auto availableSizes = icon.availableSizes();
     if (availableSizes.isEmpty() && size > 0)
         availableSizes << QSize(size, size);
 
+    auto nsImage = [[[NSImage alloc] initWithSize:NSZeroSize] autorelease];
+
     for (QSize size : qAsConst(availableSizes)) {
         QImage image = icon.pixmap(size).toImage();
         if (image.isNull())
@@ -182,12 +182,15 @@ QT_END_NAMESPACE
         [nsImage addRepresentation:[imageRep autorelease]];
     }
 
+    if (!nsImage.representations.count)
+        return nil;
+
     [nsImage setTemplate:icon.isMask()];
 
     if (size)
         nsImage.size = CGSizeMake(size, size);
 
-    return [nsImage autorelease];
+    return nsImage;
 }
 @end